Self-locking nut



Oct. 20, 1942.

c. L. BRACKETT 2,299,209

SELF-LOCKING NUT Filed May 22, 1941 2 Sheets-Sheet l CLARE L. BRACKET? emme he, so, less helitee stetes eeeeece sets-meme NUT were ill. m'echett, Detroit, Mich.

Application May 22, ieil, Sesiel Ne. 31%,?22

3 @leims. (El, Hi -21L) This invention relates to the art of lock nuts; particularly to that class of such nuts in which the locking effect is procured through radial constriction of the nut threads on the mating threads of e member with which the nut is engaged.

An object of the invention is to provide a. nut of unitary construction having means progressively operative from the base oi the hut out word, as his tightened in Work engagement, to

contract the nut bore and thus force the hut threads into firm locking engagement with the threads of its associated male threaded member.

Another object of the invention is to provide a, nut of integral construction in which separate portions of the hut body are successively moved into thread locking engagement with en esso cieted male member by compression oi the Work engaging face of the hut as it is forced egeinst the work. Other objects will be apparent from the description.

In the accompanying drawings:

Figure is a top plan view of e nut blank at an initial stage of formation;

Figuze 2 is e diemetrical section thei'ethrough;

Figure 8 is a bottom plan View oi the blank;

Figure is a top plen View of the nut in som pletetl form;

Figure 5 is e cliemetricel section theretl cugh;

Figure 6 is a, bottom pies view of the completed hut;

Figure *2 is an axial section illustrating the nut in. finger tight work: engagement;

Figure 3 is section similei' to Figure 7 but lilustratihg the hut in wrench tight full work gagement.

My improves nut is formed from e blank 9, here shown as hexagonal, with the usual email here i The work face all is provided with an integral cylindrical extension 52 which projects axially the work face with its geeripi'lery appreciably radially intvei'ei oi the hut periphery, and the extension is iormerl with e, here it tiiemettlcslly enlarged relative to the here it with which it commilcetes.

The extension bore 113 is continued smelly in wercily to e, depth lime i l which lies in plane perpendicular to the hut axis end parallel to the work face i i; so thet the plane of the depth line it? is seemed axially ehcl inwardly from the plane oi the work iece. Beyond the line it the extensi'on here is hevelerl, as at it, into cohmzueiee tioh mth the hut here. The ellametei' oi the bore is is such that the well of the extension i2 is relatively thin.

miter the nut blank is formed as shown in higs5 "ores l to 3, the extension Gil is sweeeol ihweetllt as shown iii-Figure 5 to project from the week face at an incline relative to the exis oi the hut end with its opex-e certui'e in exiei registry with the here it. The hlenl: is then cesteiloteai h cutting redial slots ltihweicily from the outer end face to suhsteotiolly hell the depth of the hut, forming the segments ill. The hose is then thread tapped, as is also the apex oi the exteh= sion; and the out is finished. It is en important feature of the invention thet the thickness of the extension i2 is such thet substantially only a single thread can he tapped therein.

Figure 1 one 8 illustrate e service eeollcetloh of the hut over the thieooled stem til of e lzolt fez: clemping together e eir o. pistes ehel l The not is finger tightened until the compeesslhle extension 22 contacts the smelt it), es shown in l e it Tool force is then required to threes the hut tulle l lome, end as the nut is rotates the sion 62 is compressed melt silly end. lily i: tl uhtii its rloekcohtect fece out the elsshe of the hut work aleee M, et which point, this to i'esultsht i'ezliel constellation, the oi the extension will have forcibly ehel tightly jammezi into lockihaz with the thyeecls with creel; aces all etlul l2 merging to give i ting The mot-lei .l of the bevel M5 creates ill temel amulet? within the Ellli; heels which it eiitl inwardly iheliheol well that meetsthe timer Lie-3e oi the extension at am ecute angle of which the apes. lines the plane of the depth lime i l ehtl substantially midway recess 225 end the pexiphery oi the hot when ec= tetlon of out h continued heyehel the point which the exteisiozo. iii been hettehed. finch eohtihuetl rotetiou reelielly cohtzreets the out here over its entire exlel extent end forces the segments ll ihweesly from their initial gcosi v ressure over the peiiphesel some it 'ercrlssfooe hettveeh the epez-i oi the Joined progressive lockingaction of the compressible extension and segmentseffects a tight grip of the nut upon the bolt that is highly resistant to vibration and to loosening even though bolt tension should be released.

The internal annular recess 2|, instead of bein formed by swaging in the extension l2, may be provided by turning in a cutting operation upon 7 the blank. It is to be understood that the dislosed embodiment is'susceptible of variation in the invention as claimed.

I claim:

, l. A self-locking nut comprising an internally threaded body provided on its work face with an etail within the limits imposed by the scope of annular axial extension inclined inwardly to the 2. A self-locking nut comprising a body having bore in jamming engagement with the threads of a male member when associated therewith to lie flush with the work face of the nut for increased work contact surface, said body being slotted from its outer end to substantially its mid-portion to provide a circumferential series of lock segments, and said bore enlargement relieving the material of the body adjacent to and behind the work face of the nut whereby the outer marginal zone of the work face provides a fulcrum on which said segments rock radially inward upon the application of work pressure beyond the point of full compression of said extension.

3. A self-locking nut comprising a body having a threaded axial bore terminating inwardly of and adjacent the nut base in a radially enlarged unthreaded recess, a thin annular extension projected'axially beyond the base of the nut at an incline thereto and apertured in registry with the threaded bore, the peripheral face of the extension aperture having therein a thread in continuation of the bore threads, said extension merging with the base of the nut inwardly of the nut periphery to provide a flat marginal zone an axial threaded bore radially enlarged adjacent the base of the nut, a substantially frusto-conical integral extension projecting axially from the nut base around the bore, the apex of said extension being apertured and threaded in conformity with the bore, said extension being compressible by work contact into the enlarged area of the nut around the periphery of the nut work face and being compressible by work contact axially inward to lie flush with the work face, and the body being radially slotted from its outer end for substantially half the depth of the nut to provide segments radially movable in a converging direction upon the application of work pressure to said flat marginal zone of the work face.

CLARE L. BRACKETT. 

